TITLE: Electromyography (EMG) Lab: Understanding Motor Unit Recruitment
INTRODUCTION:
The objective of this lab is to better understand muscle contraction and the effect it has on motor unit recruitment. This lab was done in three sections, or phases, to help understand the process of muscle contraction.
Phase 1 consisted of the usage of the electromyogram to measure varied levels of force that was generated by the muscle, the frequency, and the number of motor units recruited at different grip strengths.
Phase 2 consisted of the understanding of the recruitment of muscle fibers. Varied grip strengths were applied and recorded that allowed observances of the applied force generated by the muscle, frequency, and number of motor units …show more content…
It allowed for an understanding of muscle fatigue. Intervals of 10 seconds were recorded and observed until the maximum force was fully decreased by 50%.
During muscle relaxation, the muscle activity increases slightly. The muscle will be waiting in a relaxed but flaccid state, waiting for the next contraction. The electrical activity (also known as the motor unit recruitment) will increase within the muscles that are contracted with each stronger contraction. The brain will send progressively larger signals to the muscle to leave it primed and ready to go for the next contraction.
In this lab, as the strength of the grip increases, the applied force of the muscle will also increase. This will result in a recruitment of more motor units until a full maximum force is reached. Once the full maximum force is reached, the force applied by the muscle will then start to decrease due to muscle fatigue of the muscle fibers. This ends in a result of fewer motor units being or needed to be recruited.
EXPERIMENTAL …show more content…
2) When ready, press the play (on) button located on the electromyogram.
3) Next, slide the button on the grip strength scale to a low grip strength. Here a low grip strength of 10.3 was used; observe.
4) Then, slide the button on the grip strength scale to a medium grip strength. Here a medium grip strength of 22.3 was used; observe.
5) Now, slide the button on the grip strength scale to a high grip strength. Here a high grip strength of 75 was used; observe.
6) Lastly, slide the button on the grip strength about 20 below the high grip strength. Here a grip strength of 53 was used. Observe, as well as pause the electromyogram.
7) When at a grip strength of 53, record the force that is generated by the muscle, frequency of the nerve firings, and the number of motor units that are recruited.
Phase 2: Observing and Recording Any Muscle Recruitment
1) On the electromyogram, locate the play (on) button; press it.
2) Next, slide the button on the grip strength scale to 10.3. Pause the EMG screen.
3) When at a grip strength of 10.3, record the force generated by the muscle, frequency of nerve firings, and the number of motor units that are
INTRODUCTION:
The objective of this lab is to better understand muscle contraction and the effect it has on motor unit recruitment. This lab was done in three sections, or phases, to help understand the process of muscle contraction.
Phase 1 consisted of the usage of the electromyogram to measure varied levels of force that was generated by the muscle, the frequency, and the number of motor units recruited at different grip strengths.
Phase 2 consisted of the understanding of the recruitment of muscle fibers. Varied grip strengths were applied and recorded that allowed observances of the applied force generated by the muscle, frequency, and number of motor units …show more content…
It allowed for an understanding of muscle fatigue. Intervals of 10 seconds were recorded and observed until the maximum force was fully decreased by 50%.
During muscle relaxation, the muscle activity increases slightly. The muscle will be waiting in a relaxed but flaccid state, waiting for the next contraction. The electrical activity (also known as the motor unit recruitment) will increase within the muscles that are contracted with each stronger contraction. The brain will send progressively larger signals to the muscle to leave it primed and ready to go for the next contraction.
In this lab, as the strength of the grip increases, the applied force of the muscle will also increase. This will result in a recruitment of more motor units until a full maximum force is reached. Once the full maximum force is reached, the force applied by the muscle will then start to decrease due to muscle fatigue of the muscle fibers. This ends in a result of fewer motor units being or needed to be recruited.
EXPERIMENTAL …show more content…
2) When ready, press the play (on) button located on the electromyogram.
3) Next, slide the button on the grip strength scale to a low grip strength. Here a low grip strength of 10.3 was used; observe.
4) Then, slide the button on the grip strength scale to a medium grip strength. Here a medium grip strength of 22.3 was used; observe.
5) Now, slide the button on the grip strength scale to a high grip strength. Here a high grip strength of 75 was used; observe.
6) Lastly, slide the button on the grip strength about 20 below the high grip strength. Here a grip strength of 53 was used. Observe, as well as pause the electromyogram.
7) When at a grip strength of 53, record the force that is generated by the muscle, frequency of the nerve firings, and the number of motor units that are recruited.
Phase 2: Observing and Recording Any Muscle Recruitment
1) On the electromyogram, locate the play (on) button; press it.
2) Next, slide the button on the grip strength scale to 10.3. Pause the EMG screen.
3) When at a grip strength of 10.3, record the force generated by the muscle, frequency of nerve firings, and the number of motor units that are